linux-wandboard

[POWERPC] Fix ohare IDE irq workaround on old powermacs

Looks like a workaround for old bogus OF bitrot...  This fixes it and
hence fixes boot on some performa machines.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>